Audio systems and methods employing an array of transducers optimized for particular sound frequencies

ABSTRACT

Systems and methods for generating sound, detecting sound, and generating and detecting sound are provided. An array of audio transducers can be provided whereby each audio transducer in the array can be optimized for a narrow range of sound frequencies. When operating at or close to its resonant frequency, a transducer can generate (and/or detect) sound with a higher efficiency and less distortion as compared to other frequencies. Accordingly, sound may be divided into component signals such that each transducer is only responsible for generating (and/or detection) sound close to its resonant frequency. This sound reproduction (and/or detection) technique can increase efficiency, and therefore, can increase the total output volume that an array can generate using a given amount of input power when generating sound (and/or increase the total output power that an array can generate using a given amount of input volume when detecting sound).

CROSS-REFERENCE TO RELATED APPLICATION

This application claims the benefit of United States patent applicationSer. No. 13/163,208, filed on Jun. 17, 2011, which claims the benefit ofU.S. Provisional Application No. 61/355,984, filed Jun. 17, 2010, thedisclosures of which are both incorporated by reference herein in theirentirety.

FIELD OF THE DISCLOSURE

This can relate to systems and methods for generating sound, systems andmethods for detecting sound, and systems and methods for generating anddetecting sound.

BACKGROUND OF THE INVENTION

Traditional audio systems provide flawed audio through inefficienttechniques. For example, many traditional speakers contain only two orthree components (e.g., a subwoofer, a mid-range and a tweeter), andeach of the components is intended to cover a broad range offrequencies. However, due to the physical limitations of thesecomponents, it is incredibly difficult and expensive to producecomponents that accurately generate sound over such a broad range offrequencies. Moreover, such components typically operate in aninefficient manner that requires relatively large amounts of power.These same limiting principles can also affect the performance oftraditional microphones. Accordingly, improved audio systems are neededthat can accurately generate and/or detect sounds in an efficientmanner.

SUMMARY OF THE INVENTION

Systems and methods for accurately and efficiently generating audio areprovided. An array of audio transducers can be provided whereby one ormore audio transducers in the array can be optimized for a narrow rangeof sound frequencies. When operating at or close to its resonantfrequency, a transducer can generate sound with a higher efficiency andless distortion as compared to other frequencies. Accordingly, sound maybe divided into component signals such that each transducer is onlyresponsible for producing sound close to its resonant frequency. Thissound reproduction technique can increase efficiency, and therefore, canincrease the total output volume that an array can generate using agiven amount of input power when producing sound. Moreover, the soundreproduction technique described herein can reduce overall distortion(e.g., distortion across the frequency spectrum) of the sound generatedby the array when producing sound.

In some embodiments, an audio stream may be analyzed and then one ormore transducers in an array of transducers may be adjusted to optimizethe array for that audio stream. For example, the frequency compositionof the audio stream may be determined to identify prominent frequencybands and then the resonant frequencies of one or more transducers inthe array may be adjusted to provide better audio quality in thosebands.

In some embodiments, the same principles used to provide audio withminimal distortion can be applied to detecting audio with minimaldistortion. For example, one or more transducers in an array can beadjusted to provide high quality audio detection in prominent frequencybands for recording purposes.

In some embodiments, the same array of transducers can be used to bothgenerate and detect sound. In other embodiments, dedicated arrays oftransducers may be designed specifically for generating or detectingsound.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features of the present invention, its nature andvarious advantages will be more apparent upon consideration of thefollowing detailed description, taken in conjunction with theaccompanying drawings in which:

FIG. 1 is a schematic view of an illustrative audio system incorporatingan array of transducers in accordance with some embodiments of theinvention;

FIGS. 2A and 2B are schematic views of an illustrative array oftransducers in accordance with some embodiments of the invention

FIG. 3 is a schematic view of illustrative frequency ranges inaccordance with some embodiments of the invention;

FIG. 4 is a flowchart of an illustrative process for employing an arrayof audio transducers in accordance with some embodiments of theinvention;

FIG. 5 is a schematic view of an illustrative audio system incorporatingan array of transducers in accordance with some embodiments of theinvention;

FIG. 6 is a schematic view of illustrative frequency ranges inaccordance with some embodiments of the invention;

FIG. 7 is a flowchart of an illustrative process for employing an arrayof audio transducers in accordance with some embodiments of theinvention;

FIG. 8 is a schematic view of an illustrative audio system incorporatingan array of transducers in accordance with some embodiments of theinvention; and

FIG. 9 is a flowchart of an illustrative process for employing an arrayof audio transducers in accordance with some embodiments of theinvention.

DETAILED DESCRIPTION

In accordance with the disclosure, an array of audio transducers can beprovided and each audio transducer in the array can be optimized for anarrow range of sound frequencies. For example, each transducer in thearray can have one or more physical characteristics that renders itideal for producing (and/or detecting) sound within a narrow range offrequency (e.g., an optimum frequency or a resonant frequency). Whenoperating at or close to its optimum frequency, the transducer cangenerate (and/or detect) sound with a higher efficiency and lessdistortion as compared to other frequencies. In some embodiments, thetransducer may efficiently generate (and/or detect) sound at or close toits optimum frequency because the transducer's mechanical structure willnaturally encourage vibrations at that frequency. In some embodiments,the transducer may generate (and/or detect) sound at or close to itsoptimum frequency with minimal distortion because the acoustic volumebehind the transducer may be optimized so that any reflections off theback surface do not destructively interfere with the output sound.

FIG. 1 includes audio system 100 incorporating an array of transducersin accordance with some embodiments. System 100 can include source 110,converter 120, and transducers 131-134. Source 110 can be any source ofaudio signals or data. In some embodiments, source 110 can be a sourceof analog audio signals. For example, source 110 can be a media playeror communications device that provides analog audio signals as output.In some embodiments, source 110 can be a source of digital audio data.For example, source 110 can be storage or memory on which data is storedas a digital file.

Transducers 131-134 can each be any suitable audio transducer forgenerating sound. For example, one or more of transducers 131-134 may beoperable to generate sound waves in response to electrical signals(e.g., a speaker driver). Each of transducers 131-134 may be designed togenerate a different narrow range of sound frequencies in an efficientand distortion-free manner. In some embodiments, one or more oftransducers 131-134 may include conductive material coupled with orintegrated into a diaphragm. Continuing the example, electric signalsmay be passed through the conductive material to control the diaphragmand thereby generate audio waves through electromagnetic induction.

In some embodiments, each of transducers 131-134 can be optimized for adifferent range of sound frequencies. For example, Transducer A 131 maybe designed to generate sound at the highest range of frequencies thatsystem 100 can handle, Transducer B 132 may be designed to generatesound at the next lowest range of frequencies and so forth. In thismanner, the array of transducers 131-134 may be designed to collectivelycover the audible spectrum. In some embodiments, each of transducers131-134 may be designed so that the transducer's resonant frequency islocated squarely in the middle of its respective range of frequencies.If each of transducers 131-134 are designed in this manner and thefrequency ranges are sufficiently narrow, each transducer may only beresponsible for generating audio within a narrow range around itsresonant frequency. Limiting the range of operation to a narrow rangeenables each transducer to operate with the least amount of distortionand power loss.

It is understood that any number of transducers can be used inaccordance with the disclosure. However, in accordance with someembodiments of the invention, it may be advantageous to employ a largenumber of transducers so that the range of frequencies which eachtransducer has to generate is relatively narrow. Accordingly, the moretransducers that are provided in the array, the higher the quality ofaudio that is produced and at an expense of less power loss.

Therefore, a system may include a relatively large number oftransducers. For example, a system may include 20 or more audiotransducers; 50 or more audio transducers; 100 or more audiotransducers; 200 or more audio transducers; 500 or more audiotransducers; 1,000 or more audio transducers; 5,000 or more audiotransducers; 10,000 or more audio transducers; 50,000 or more audiotransducers or 100,000 or more audio transducers.

In some embodiments, the number of transducers in a system may vary overtime. For example, a system may be configurable so that a user can addor remove transducers from the system. In some embodiments, transducersmay be grouped in physical units with separate housings or substrates sothat entire groups of transducers can be added or removed from thesystem. In another example, a system may test transducers and maydisconnect (e.g., effectively remove) non-working or damaged transducersfrom the system while still maintaining the production (and/ordetection) of quality audio.

Converter 120 may be electrically coupled to both source 110 andtransducers 131-134. In some embodiments, converter 120 may beelectrically coupled with source 110 and/or transducers 131-134 throughone or more conductors (e.g., traces, wires or cables). In someembodiments, converter 120 may be coupled with source 110 and/or one ormore of transducers 131-134 through a wireless communications interface.Converter 120 can include any suitable circuitry for processing audio,including one or more processors, one or more digital signal processors,one or more amplifiers, one or more crossovers, one or more filters, anyother suitable circuitry, or any suitable combination thereof. Converter120 can receive audio streams from source 110 (e.g., through analogsignals or digital data), convert the audio streams, and then transmitcontrol signals to transducers 131-134. Converter 120 may divide audiostreams received from source 110 into different component signalscorresponding to different frequency ranges. For example, each componentsignal may have a frequency range that is centered on a resonantfrequency of a respective one of transducers 131-134. Component signalscan be transmitted, in a synchronized manner, to transducers 131-134 forcollectively producing sound based on the entire audio stream. Bysending each transducer a component signal with frequenciespredominantly or solely at or near the resonant frequency of thetransducer, the transducer can efficiently produce that portion of thesound with minimal distortion. The combined sound produced by all oftransducers 131-134 may therefore be of a high quality.

If source 110 provides an audio stream that includes an analog audiosignal, converter 120 may divide the analog signal into component analogsignals, and transmit each of the component signals to a respective oneof transducers 131-134 for sound generation. If source 110 provides anaudio stream that includes digital audio data, converter 120 may, insome embodiments, convert the digital audio data into an analog signaland then process the analog signal as discussed above. In otherembodiments, converter 120 may divide the digital audio data intocomponent data streams corresponding to different frequencies orfrequency ranges, and transmit each of the component data streams to arespective one of transducers 131-134 for conversion to analog and soundgeneration.

In some embodiments, the operation of a converter (e.g., converter 120)may be based at least partially on the transducers coupled with theconverter. For example, converter 120 may divide an audio stream into asmany component signals as there are transducers, and therefore resonantfrequencies, in an array. In some embodiments, the frequency range ofeach component signal may be based at least partially on the resonantfrequency of a respective transducer in the system. For example, thefrequency range of a component signal may be a narrow frequency rangecentered over the resonant frequency of a corresponding transducer. Insome embodiments, the size of the frequency ranges of each componentsignal may be based at least partially on how many transducers are in anarray or the space between the resonant frequencies. In situations wherethere are many transducers and a large number of resonant frequencies,the frequency ranges of each component signal may be even narrower.

It is understood that transducers of any type can be employed inaccordance with this disclosure. For example, an array of piezoelectrictransducers, magnetostrictive transducers, electrostatic transducers,ribbon magnetic transducers, planar magnetic transducers, bending wavetransducers, flat panel transducers, distributed mode transducers, heilair motion transducers, plasma arc transducers or any combinationthereof can be used. In some embodiments, smaller transducers may beadvantageous because they may minimize space constraints on the numberof transducers. For example, micrometer-scaled transducers can bemanufactured through techniques in accordance withmicroelectromechanical systems (MEMS) and employed in accordance withthis disclosure.

FIG. 2A includes array 200 of transducers in accordance with someembodiments. Array 200 can include audio transducers 210, 220, 230, 240,250, 260, 270, 280, and 290 (see, e.g., transducers 131-134 of system100). Each of the transducers in array 200 may be of a micrometer scaleand manufactured using MEMS techniques. Each transducer may include adiaphragm, a conductive member, and one or more control lines coupled tothe conductive member. For example, transducer 240 can include diaphragm241, conductive path 246, and control line 247 coupled with conductivepath 246. A diaphragm may be a flexible membrane formed from anysuitable material. For example, diaphragm 241 may be a polymer membrane.Coupled with or integrated into its diaphragm, each audio transducer mayinclude a conductive path. For example, transducer 240 may include path246 formed from a conductive material. In some embodiments, path 246 maybe formed by depositing a conductive metal onto the surface of adiaphragm.

Each audio transducer may also include a control line electricallycoupled with the conductive path. For example, audio transducer 240 mayinclude control line 247 for transmitting electrical signals to and frompath 246. A control line can include one or more conductors. In someembodiments, a control line may include an active conductor and a returnconductor. In some embodiments, a control line may include only anactive conductor and two or more transducers in an array may employ acommon return conductor. A control line may be formed from anyconductive material, including, for example, a conductive trace or wire.In accordance with the disclosure, it is understood that a control linemay also be used as an incoming signal line when detecting sounds.

In some embodiments, as shown in FIG. 2B, each transducer may include acavity located beneath the diaphragm. For example, transducer 240 mayinclude cavity 243, transducer 250 may include cavity 253, andtransducer 260 may include cavity 263. Such cavities may be formed bymicromachining or etching away a substrate in which one or moretransducers is located. For example, transducers 240, 250, and 260 maybe located on substrate 298 and cavities 243, 253, and 263 may be formedby etching away portions of substrate 298. In some embodiments, one ormore audio transducers may be located on a silicon substrate and knowntechniques for integrated circuit manufacturing can be used for etchingand/or depositing conductive materials.

In some embodiments, a magnetic or electrically charged component may beprovided adjacent to one or more of the audio transducers. Such magneticor electrically charged component may provide a magnetic field for thepurposes of generating (and/or recording) sound using a flexiblediaphragm and electromagnetic induction. For example, electricallyconductive plating 299 may be provided on the opposite side of substrate298 from transducers 240, 250, and 260. Continuing the example, plating299 may be electrically charged so that, when a potential is applied toconductive paths 246, 256, or 266, a respective one of diaphragms 241,251, and 261 can be displaced by electromagnetic induction and generatea sound wave. As another example, plating 299 may be electricallycharged so that, when a sound wave displaces diaphragms 241, 251, and261 the current flowing through conductive paths 246, 256, or 266 may bealtered to generate an electric signal through electromagneticinduction.

The resonant frequency of each transducer in an array may be a functionof any suitable characteristic or combination of characteristics of thetransducer. In some embodiments, the resonant frequency of one or moretransducers in an array may be a function of the rigidity or flexibilityof the material from which its diaphragm is formed. For example, moreflexible materials may lead to higher resonant frequencies because thediaphragm may move more easily, while less flexible materials may leadto lower resonant frequencies because the diaphragm may not be displacedas easily. In some embodiments, the resonant frequency of one or moretransducers in an array may be a function of the transducer's cavity(e.g., the volume, depth, or shape of the cavity). For example, largercavities may lead to lower resonant frequencies because a larger amountof air in a transducer's cavity may allow the transducer's diaphragm totravel a greater distance while a smaller amount of air may be lesscompressible and, therefore, not allow the transducer's diaphragm totravel as great of a distance. In some embodiments, the resonantfrequency of one or more transducers in an array may be a function ofwhether or not its cavity includes an acoustic port, the number ofacoustic ports in its cavity, the size of any acoustic ports in itscavity, or any combination thereof. For example, cavity 243 may includeacoustic port 244 and the port may have an effect on the resonantfrequency of transducer 240. In some embodiments, the installation ofone or more ports may lead to lower resonant frequencies because a portcan allow for free movement of air into the transducer's cavity and,therefore, greater deflection of the transducer's diaphragm. Likecavities themselves, ports can be formed by etching away a substrate orusing any other suitable technique.

While the discussion of array 200 relates to MEMS audio transducers, itis understood that audio transducers of other sizes and types, such asthose previously discussed, can be used in accordance with thisdisclosure.

FIG. 3 includes chart 300 of illustrative frequency ranges in accordancewith some embodiments. Chart 300 includes a scale of frequencies andnumerous frequency ranges on the scale. In this illustrative embodiment,the frequency ranges are labeled from A to DD. Frequency ranges may beused to determine how an audio stream is divided into component signalsfor distribution amongst an array of transducers (see, e.g., system100). For example, marker 302 can correspond to a resonant frequency ofa particular transducer (e.g., one of transducers 131-134) and Range Gmay be centered over that resonant frequency. Accordingly, if acomponent signal that predominantly has frequencies within Range G istransmitted to the corresponding transducer, the transducer mayefficiently produce sound with minimal distortion.

While chart 300 includes 30 frequency ranges for use with an array ofaudio transducers, it is understood that any number of frequency rangesand corresponding audio transducers can be used in accordance with thedisclosure. For example, 20 or more; 50 or more; 100 or more; 200 ormore; 500 or more; 1,000 or more; 5,000 or more; 10,000 or more; 50,000or more; 100,000 or more; or any other suitable number of frequencyranges and corresponding audio transducers can be used without deviatingfrom the spirit and scope of the disclosure. In some embodiments, morefrequency ranges and audio transducers may lead to narrower frequencyranges and, therefore, greater efficiency and higher quality becauseeach transducer will only be required to generate (and/or detect) audionear its resonant frequency.

FIG. 4 includes process 400 for employing an array of audio transducersin accordance with some embodiments of the invention. For example,process 400 can be used to efficiently generate high quality audio withan array of audio transducers. Process 400 can be performed by an audiosystem that includes an array of transducers (e.g., system 100). Atblock 410, an array of transducers can be analyzed. An array oftransducers can be analyzed by passively or actively measuring one ormore electrical characteristic of the transducer leads (e.g.,resistance, impedance, voltage, current, inductance, capacitance,frequency response or any combination thereof).

Block 410 can include analyzing an array of transducers to determine anysuitable characteristic of the array. For example, an array oftransducers can be analyzed to determine the number of transducers inthe array, the resonant frequencies of the transducers in the array, therelative locations of the transducers in the array, the maximum volumeoutput of the transducers in the array, the condition of the transducersin the array (e.g., whether any transducers have incurred mechanical orthermal damage), any other suitable characteristic of the array, or anycombination thereof. At block 420, an audio stream can be received. Forexample, an audio stream may be received from a source (see, e.g.,source 110 shown in FIG. 1). An audio stream may be received from acomponent within an audio system (e.g., source 110 within system 100) orfrom an external source (e.g., a portable media player or an internetserver). An audio stream received at block 420 can include one or moreanalog signals, one or more digital signals, or any combination thereof.

At block 430, the audio stream can be converted into component signalsbased on the analysis performed at block 410. Any characteristic of thetransducer array determined at block 410 may be used to control theconversion of the audio stream at block 430. For example, the conversionof the audio stream may be based on the number of audio transducers orthe resonant frequencies of the audio transducers.

In some embodiments, the number of component signals created at block430 may depend on the analysis performed at block 410. For example, ifthe analysis performed at block 410 indicates that an array includes acertain number of transducers, the audio stream may be converted into acorresponding number of component signals.

In some embodiments, one or more characteristics of the componentsignals created at block 430 may be based on one or more characteristicsof the transducer array. For example, a component signal may correspondto a particular transducer in the array and the range of frequenciesincluded in the component signal may be centered over the resonantfrequency of the particular transducer. Accordingly, the particulartransducer can accurately and efficiently generate sound based on thecorresponding component signal. In some embodiments, each componentsignal generated at block 430 may correspond to a respective transducer,and the frequency range of each component signal may match the resonantfrequency of the corresponding transducer. If there are a substantialnumber of transducers in the array, each component signal may benarrowly tailored to the resonant frequency of a correspondingtransducer and the accuracy and efficiency of the system can bedrastically improved.

In some embodiments, a process may operate an array of transducers in amanner that decreases the chances of or completely prevents thetransducers from “blowing out” (e.g., incurring mechanical or thermaldamage). For example, converting an audio stream into component signalsnarrowly optimized for each transducer may decrease the chances thateach transducer incurs mechanical or thermal damage. In someembodiments, a process may include analyzing one or more componentsignals to ensure that each component signal will not damage thecorresponding transducer. For example, the converting performed at block430 may include analyzing the component signals to ensure that thesignals will not damage any of the transducers in the array (e.g.,analyzing the magnitude and/or frequencies of the component signals).

At block 440, each of the component signals can be transmitted to adifferent transducer in the array of transducers. Each component signalmay be transmitted to a respective transducer so that the frequencyrange of the component signal corresponds to the resonant frequency ofthe transducer (e.g., is approximately centered over the resonantfrequency of the transducer). For example, each component signal may betransmitted to a corresponding transducer in the array, and thetransducer can accurately and efficiently generate sound based on thecomponent signal.

In some embodiments, a process may operate an array of transducers tocompensate if one or more of the transducers is faulty or has incurredmechanical or thermal damage. If one or more faulty or damagedtransducers are identified, those transducers may be effectively removedfrom service and component signals may no longer be transmitted to thefaulty or damaged transducers. Moreover, unlike a traditional speakerthat can be totally impaired if it is damaged, other transducers in thearray may still be able to generate distortion-free audio even if someof the transducers are damaged. For example, block 410 may includedetermining whether any of the transducers in the array are damaged,block 430 may include converting the audio stream into component signalsthat only correspond to undamaged transducers and block 440 may includetransmitting component signals to only the undamaged transducers.

In some embodiments, a system can include an array of dynamictransducers that can be adjusted to provide increased accuracy andefficiency. For example, the system may analyze an audio stream and thendynamically adjust one or more transducers in the array based on theanalysis of the stream. Continuing the example, component signals may becreated and transmitted to the array after adjustment for accurate andefficient sound generation.

FIG. 5 includes audio system 500 incorporating an array of transducersin accordance with some embodiments. System 500 can include source 510,controller 520, and transducers 531-534. Source 510 can be any suitablesource of audio streams. For example, source 510 can be substantiallysimilar to source 110, as described above in connection with FIG. 1, andthe previous description of the latter can be applied to the former.

Transducers 531-534 can each be a dynamic audio transducer forgenerating sound. Like transducers 131-134, each of transducers 531-534can be used to generate sound based on an electrical signal. However,transducers 531-534 differ from transducers 131-134 in that transducers531-534 may be dynamically configurable to change the resonant frequencyof one or more transducers. For example, each of transducers 531-534 maybe formed from a material that can be electrically adjusted to changethe resonant frequency of the transducer. In some embodiments,transducers 531-534 may each include a material that changes one or morephysical properties, such as rigidity, when an electrical potential orcurrent is applied to the material. For example, transducers 531-534 mayeach include a diaphragm that is formed from a material that changesrigidity when an electrical potential is applied to the material.Continuing the example, a change in the rigidity of a transducer'sdiaphragm can result in a change of the resonant frequency of thetransducer and, therefore, the resonant frequencies of transducers531-534 may be adjustable. In this manner, transducers 531-534 may bedynamically adjusted based on an audio stream. For example, a system mayanalyze an audio stream to determine the frequency composition of thestream, adjust one or more transistors based on the analysis, and thencreate corresponding composition signals based on the adjustment.

While the embodiments shown in FIGS. 1 and 5 show separate systems thatinclude static and dynamic transducers, it is understood that a systemmay include a combination of static transducers and dynamic transducerswithout deviating from the scope of the disclosure. For example, asystem may include an array of static transducers covering the standardrange of frequencies for audio streams, and the system may also includea number of dynamic transducers for use as supplemental transducers. Insome embodiments, the dynamic transducers can be used as spares if oneor more of the static transducers is faulty or becomes damaged. In someembodiments, the dynamic transducers can be used to augment statictransducers for frequency ranges that are especially prominent in anaudio stream.

Controller 520 may be electrically coupled to both source 510 andtransducers 531-534. Controller 520 can include any suitable circuitryfor processing audio and adjusting one or more of transducers 531-534,including one or more processors, one or more digital signal processors,one or more amplifiers, one or more crossovers, one or more filters, anyother suitable circuitry, or any suitable combination thereof. Likeconverter 120 (shown in FIG. 1), controller 520 may receive an audiostream from source 510 and provide component signals to transducers531-534. However, controller 520 may include circuitry for analyzing theaudio stream and dynamically adjusting transducers 531-534 based on theanalysis. For example, controller 520 may analyze the audio stream inreal time as it is received. Continuing the example, controller 520 maythen adjust the resonant frequencies of transducers 531-534 so that thearray of transducers is configured to focus on the prominent frequenciesor frequency ranges in the given audio stream.

In some embodiments, controller 520 may be coupled to each of thetransducers through multiple electrical paths (see, e.g., control line247 shown in FIG. 2A). For example, controller 520 may coupled to eachtransducer in the array through one or more electrical paths fortransmitting component signals as well as one or more electrical pathsfor controlling transducer adjustments. In some embodiments, controller520 may be coupled to each of the transducers through one or moreelectrical paths can both transmit component signals and controltransducer adjustments. For example, electrical signals of a certainmagnitude or frequency can be used to control transducer adjustmentswhile other electrical signals can transmit component signals.

FIG. 6 includes chart 600 of illustrative frequency ranges in accordancewith some embodiments. Chart 600 includes an audio stream's frequencycomposition 601 and various frequency ranges (see, e.g., groups 602-604)that are based on the audio stream's frequency composition. As seen incomposition 601, the audio stream is predominantly composed offrequencies within two bands. In order to provide accurate and efficientsound, an audio system can provide a higher resolution of frequencyranges in these two bands. For example, frequency ranges in groups 602and 604, which are labeled C to J and R to FF and correspond to the twobands featured in composition 601, may be narrower than the frequencyranges in group 603, which are labeled K to Q. Continuing the example,an array of transducers (see, e.g., transducers 531-534 shown in FIG. 5)may be adjusted so that the transducers' resonant frequencies correspondto the frequency ranges shown in FIG. 6. Accordingly, the system cangenerate sound in at least the prominent frequency bands with highaccuracy and efficient power use. In accordance with the disclosure, thesound generated for the less important frequency bands may have lessaccuracy or efficiency but this may not be noticeable to an averagelistener (e.g., because those frequency bands carry less audio content).

While chart 600 includes 33 frequency ranges for use with an array ofaudio transducers, it is understood that any number of frequency rangesand corresponding audio transducers can be used in accordance with thedisclosure. Moreover, any suitable technique can be used to configurefrequency ranges based on the analysis of an audio stream. In someembodiments, rather than narrowing the frequency ranges in groups 602and 604, a system may leave the ranges at a standard width but simplyassign multiple transducers to each range so that the range can begenerated at a higher volume. In some embodiments, a system may taketransducers corresponding to less important frequency ranges (e.g.,ranges in group 603) and reassign the transducers to the more prominentfrequency ranges (e.g., ranges in groups 602 or 604).

FIG. 7 includes process 700 for employing an array of audio transducersin accordance with some embodiments of the invention. Process 700 may beemployed in conjunction with an array of dynamic transducers that can beadjusted to accurately and efficiently generate sound (see, e.g.,transducers 531-534 shown in FIG. 5). For example, process 700 can beused to dynamically adjust an array of audio transducers and efficientlygenerate high quality audio with the array. Process 700 can be performedby an audio system that includes an array of transducers (e.g., system500 and transducers 531-534).

At block 710, an audio stream can be analyzed. The audio stream may beanalyzed to determine one or more suitable characteristics of thestream. For example, the audio stream may be analyzed to determine theaudio stream's frequency composition (see, e.g., composition 601 shownin FIG. 6). In accordance with this disclosure, any suitable techniquecan be used to analyze the audio stream and determine the audio stream'sfrequency composition. In another example, the audio stream may beanalyzed to determine the audio stream's average volume. Like the audiostream received in process 400 (see FIG. 4), the audio stream analyzedat block 710 may be analog or digital. In some embodiments, process 700may include converting an audio stream from analog to digital or fromdigital to analog before performing the analysis at block 710.

At block 720, at least one transducer from an array of transducers maybe adjusted based on the analysis. The at least one transducer may beadjusted by changing the transducer's resonant frequency. For example,an electrical potential may be applied across an element of thetransducer and the transducer's resonant frequency may change based onthe potential. In some embodiments, the resonant frequency of one ormore transducers may be changed based on a frequency range resultingfrom the analysis. As previously explained, frequency bands that areprominently featured in an audio stream may correspond to narrowerfrequency ranges (see, e.g., frequency range groups 602 and 604 shown inFIG. 6), while frequency bands that are less emphasized may correspondto wider frequency ranges (see, e.g., frequency range group 603 shown inFIG. 6). Accordingly, the resonant frequencies of one or moretransducers may be adjusted to customize the transducers for therespective frequency ranges and, therefore, optimize the accuracy andefficiency of the audio system around the frequencies that are prominentin the audio stream. In some embodiments, every transducer in the arraymay be adjusted based on the analysis. For example, every audiotransducer in the array may be adjusted based on the analysis so thatthe array is completely customized for accurately and efficientlyproducing sound from the audio stream.

At block 730, the audio stream is converted into component signals. Eachcomponent signal may correspond to a frequency range (see, e.g., chart600 shown in FIG. 6). In some embodiments, the adjustments performed atblock 720 may affect the component signals created at block 730. Forexample, the component signals created at block 730 may be based onfrequency ranges that correspond to the adjusted array of transducers.In some embodiments, block 720 and block 730 may occur simultaneously.For example, at least one transducer may be adjusted while the audiostream is converted into component signals. In this manner, lessbuffering may be necessary to perform process 700 in real time.

In some embodiments, the converting performed at block 730 may includeanalyzing the component signals to ensure that the signals will notmechanically or thermally damage any of the transducers in the array(e.g., analyzing the magnitude of the component signals).

At block 740, each of the component signals are transmitted to adifferent transducer in the array of transducers. Each component signalmay be transmitted to a respective transducer so that the frequencyrange of the component signal corresponds to (e.g., is approximatelycentered over) the resonant frequency of the transducer, which may havebeen adjusted at block 720. After transmission to the array oftransducers, the adjusted transducers can then provide the soundaccurately and efficiently.

While process 700 describes analyzing an audio stream and makingadjustments accordingly, it is understood that the teachings of process700 can be combined with those of process 400 without deviating from thespirit and scope of the disclosure. For example, in addition toanalyzing an audio stream, process 700 may include analyzing an array oftransducers (see, e.g., block 410 shown in FIG. 4). Continuing theexample, adjusting one or more of the transducers (block 720) and/orconverting the audio stream into component signals (block 730) may bebased on the analysis of the array, including such features as thenumber of audio transducers or the unadjusted (i.e., natural) resonantfrequencies of the audio transducers. Moreover, process 700 mayincorporate the techniques disclosed in connection with process 400 foravoiding transducer damage or compensating in response to faulty ordamaged transducers. In some embodiments, a process may only incur anegligible decrease in audio quality based on a faulty or damagedtransducer because the undamaged transducers may be dynamically adjustedto cover the frequency range corresponding to the faulty or damagedtransducer. For example, block 720 may include adjusting at least onetransducer from an array to compensate for any faulty or damagedtransducers, block 730 may include converting the audio stream intocomponent signals that only correspond to undamaged transducers andblock 740 may include transmitting component signals to only theundamaged transducers.

The same principles underlying the previous descriptions of accuratelyand efficiently generating sound through an array of transducers can beused to accurately and efficiently detect sound. For example, an arrayof transducers can be used to detect sound, but each transducer may besubject to a different filter so that each transducer only contributes anarrow range of frequencies centered around the transducer's resonantfrequency. This narrow range of frequencies around a transducer'sresonant frequency may provide the most accurate measurements possiblefrom each transducer. In accordance with the disclosure, such detectionfunctionality can be provided by an array of transducers that is alsocapable of generating sound (see, e.g., transducer arrays discussed inconnection with FIGS. 1-7) or by an array of transducers that isspecially designed for detecting sound.

FIG. 8 includes audio system 800 incorporating an array of transducersin accordance with some embodiments. System 800 can include storage 810,controller 820, and transducers 831-834. Storage 810 can be any storageor memory for storing audio signals or data. In some embodiments,storage 810 can store analog audio signals (e.g., on a magnetic tape).In some embodiments, storage 810 can store digital audio data (e.g., ona hard disk drive or flash memory). In some embodiments, storage 810 canstore metadata information related to audio signals or data. Forexample, metadata information may include information related tocontroller 820 or one or more of transducers 831-834. In someembodiments, such information may be used when recreating a sound fromthe stored audio signal or data.

Transducers 831-834 can each be any suitable audio transducer fordetecting sound. In some embodiments, one or more of transducers 831-834can be a sound detection device (e.g., a microphone transducer)optimized for a particular frequency. In some embodiments, one or moreof transducers 831-834 may include conductive material coupled with orintegrated into a diaphragm and, when the diaphragm is moved by audiowaves, the current flowing through the conductive material may bealtered to generate an electric signal through electromagneticinduction.

In some embodiments, each of transducers 831-834 can also be capable ofgenerating sound. For example, transducers 831-834 may be substantiallysimilar to transducers 131-134 shown in FIG. 1 or transducers 531-534shown in FIG. 5 and transducers 831-834 may be substituted for thosetransducers in their respective systems.

In some embodiments, one or more of transducers 831-834 may include aphysical filter that controls which sound frequencies reach eachtransducer. Providing such physical filters can prevent interference oreven transducer damage from sounds that are well outside the narrowrange of frequencies that a transducer is optimized to receive. Forexample, each of transducers 831-834 may include a different screencovering the transducer so that each transducer receives a differentrange of frequencies, and that range may correspond generally to thetransducer's resonant frequency. In some embodiments, physical filtersprovided with transducers 831-834 may allow relatively wide ranges offrequencies to pass so that each of transducers 831-834 can be adjustedto detect a relatively narrow range of frequencies within the physicalfilter's range. In some embodiments, no physical filters may be providedwith transducers 831-834.

Controller 820 may be electrically coupled to both storage 810 andtransducers 831-834. In some embodiments, controller 820 may beelectrically coupled with storage 810 and/or transducers 831-834 throughone or more conductors (e.g., traces, wires or cables). In someembodiments, controller 820 may be coupled with storage 810 and/or oneor more of transducers 831-834 through a wireless communicationsinterface. Controller 820 can include any suitable circuitry forprocessing audio, including one or more processors, one or more digitalsignal processors, one or more amplifiers, one or more crossovers, oneor more filters, any other suitable circuitry, or any suitablecombination thereof.

Controller 820 can receive audio signals or data from one or more oftransducers 831-834 and combine them into a collective signal, datastream or data file.

In some embodiments, controller 820 may dynamically adjust one or moreof transducers 831-834. For example, controller 820 may adjust theresonant frequency of one or more of transducers 831-834. In someembodiments, controller 820 may dynamically adjust the resonantfrequency of one or more transducers based on previously received audiosignals so that the array can be configured to accurately detect futureaudio signals. For example, if the received audio signals indicateprominent frequency bands, the array of transducers may be configured sothat there is a higher resolution in those frequency bands (see, e.g.,frequency range groups 602 and 604 shown in FIG. 6). In someembodiments, system 800 may periodically analyze previously receivedaudio signals and configure the array of transducers accordingly so thatthe transducers are regularly updated as the received audio signalschange.

In some embodiments, controller 820 may filter the audio signals or datareceived from each transducer based on the resonant frequency of eachtransducer or a range around the resonant frequency of each transducer.For example, controller 820 may apply filters with window functions toeach received signal or data, and each window function may be centeredaround the resonant frequency of the audio transducer from which thesignal is received. In other words, each filter may only permit a narrowrange of frequencies near the resonant frequency of each transducer andrestrict all other frequencies. Once the received signals have beenfiltered, controller 820 may combine the filtered signals or data tocreate a collective audio stream. For example, controller 820 may addtogether each filtered signal or data stream to generate a collectiveaudio stream representing the entire range of sound detected by thearray of transducers 831-834.

Controller 820 may transmit the audio stream to storage 810 for storage.In some embodiments, controller 820 may convert an audio stream beforetransmitting it to storage 810. For example, controller 820 may convertan analog audio signal within the audio stream to digital data ifstorage 810 is not able to store analog audio signals. In someembodiments, storage 810 may be able to store both analog audio signalsand digital data and conversion may be unnecessary.

FIG. 9 includes process 900 for employing an array of audio transducersin accordance with some embodiments of the invention. For example,process 900 can be used to detect high quality audio with an array ofdynamic audio transducers. Process 900 can be performed by an audiosystem that includes an array of transducers (e.g., system 800 andtransducers 831-834). At block 910, a component audio signal can bereceived from an array of transducers. For example, an array oftransducers (see, e.g., transducers 831-834 shown in FIG. 8) cangenerate at least one component audio signal based on sound and then thesignal can be received by a controller (see, e.g., controller 820 shownin FIG. 8). In some embodiments, the array of transducers can generate aplurality of component audio signals at block 910. For example, eachtransducer in the array can generate a different component audio signaland the component audio signals can then be received by a controller.

At block 920, one or more component audio signals can be analyzed. Forexample, a controller (see, e.g., controller 820 shown in FIG. 8) cananalyze one or more incoming component audio signals to determine thefrequency composition of the collective sound (see, e.g., composition601 shown in FIG. 6). In some embodiments, every component audio signalreceived at block 910 can be analyzed at block 920. In some embodiments,the one or more component audio signals may be analyzed individually. Insome embodiments, the one or more component audio signals may first becombined and then analyzed collectively.

At block 930, at least one transducer from the array may be adjustedbased on the analysis. For example, the resonant frequencies of one ormore transducers from the array may be adjusted so that the array isoptimized to detect the collective sound. In some embodiments, theresonant frequencies of one or more transducers from the array may beadjusted to provide a higher resolution of audio detection (see, e.g.,frequency range groups 602 and 604 shown in FIG. 6). Accordingly, thearray may be able to more accurately detect the sound in the mostimportant frequencies.

At block 940, additional component audio signals may be received fromthe array of transducers. For example, each transducer in an array mayreceive a different incoming component audio signal at block 940. Thecomponent audio signals received at block 940 may be considered “second”component audio signals because they are received after a componentaudio signal received at block 910. The signals received at block 940may be received after the one or more transducers have been adjusted. Inother words, the audio signals received at block 940 may be receivedthrough transducers which have been adjusted based on the frequenciesthat were detected at block 910 (e.g., a relatively short time beforeblock 940). Accordingly, the component audio signals received at block940 may be more useful for accurately detecting sound.

At block 950, the “second” component audio signals may be filtered basedon the adjusting. For example, the signals received at block 940 may befiltered so that each transducer in the array contributes a frequencyrange tailored to its resonant frequency, which may have been adjustedat block 930. In some embodiments, each component audio signal may befiltered using a window filter that only passes a frequency rangecentered around the corresponding transducer's resonant frequency. Aspreviously discussed, the resonant frequency of one or more transducersmay have been adjusted at block 930. Moreover, the width of thefrequency range allowed to pass through the filter may be based on theproximity of neighboring frequency ranges, one or more of which may havealso been adjusted at block 930. Accordingly, the component audiosignals can be filtered based on the adjusting performed at block 930.

At block 960, the filtered audio signals can be combined into an audiostream. For example, the results of the filtering can be combined intoan audio stream that represents the total sound detected by the array.In situations where each transducer contributes only frequencies thatare closely related to the transducer's respective resonant frequency,the audio stream may have a higher quality with minimal distortions. Insome embodiments, process 900 may further include transmitting the audiostream to a storage unit (see, e.g., storage 810 shown in FIG. 8) forstoring.

In some embodiments, a sound detection process (e.g., process 900 shownin FIG. 9) may operate an array of transducers to compensate if one ormore of the transducers is faulty or has incurred mechanical or thermaldamage. If one or more faulty or damaged transducers are identified,those transducers may be effectively removed from service and theprocess may no longer use component signals from the faulty or damagedtransducers to form the final audio stream. Moreover, unlike atraditional microphone that can be totally impaired if it is damaged,other transducers in the array (and potentially the array as a whole)may still be able to receive high quality audio even if some of thetransducers are damaged. For example, block 920 may include determiningwhether any of the transducers in the array are damaged, block 930 mayinclude adjusting at least one transducer from the array of transducersto compensate for a damaged transducer and block 960 may include onlycombining filtered audio signals that correspond to undamagedtransducers.

In some embodiments, systems may be able to both detect and generatesound accurately and efficiently. For example, system 500 (shown in FIG.5) may be able to provide the same functionality as system 800 andvice-versa. In some embodiments, a single array of transducers canperform the functions previously described with respect to bothtransducers 531-534 and transducers 831-834. For example, eachtransducer in an array may be able to both generate sound based on anelectrical signal and generate an electrical signal based on sound. Insome embodiments, a single unit of circuitry can perform the functionspreviously described with respect to both controller 520 and controller820. For example, controller 520 may be operative to assist in sounddetection by combining audio signals or data received from transducers531-534. As another example, controller 820 may be operative to assistin sound generation by dividing an audio signal or data stream intocomponent signals or data streams and transmitting the component signalsor data streams to transducers 831-834. Accordingly, system 500 may beable to perform both process 700 and process 900 and system 800 may beable to perform both process 700 and process 900. In some embodiments, aconverter may operate in different modes (e.g., sound generation andsound detection), and the converter may change modes based on a userinput or other suitable event. In some embodiments, a single unit ofcircuitry can perform the functions previously described with respect toboth source 510 and storage 810. For example, a single component mayfunction as both a source of audio signals or data streams representingaudio signals and a storage location for detected audio signals or datastreams representing detected audio signals.

The various embodiments of the invention may be implemented by software,but can also be implemented in hardware or a combination of hardware andsoftware. The invention can also be embodied as computer readable codeon a computer readable medium. The computer readable medium can be anydata storage device that can store data which can thereafter be read bya computer system. Examples of a computer readable medium includeread-only memory, random-access memory, CD-ROMs, DVDs, magnetic tape,and optical data storage devices. The computer readable medium can alsobe distributed over network-coupled computer systems so that thecomputer readable code is stored and executed in a distributed fashion.

The above described embodiments of the invention are presented forpurposes of illustration and not of limitation. It is understood thatone or more features of an embodiment can be combined with one or morefeatures of another embodiment to provide systems and/or methods withoutdeviating from the spirit and scope of the invention.

What is claimed is:
 1. An array of transducers, comprising: a pluralityof transducers, each transducer comprising: a diaphragm; a conductivepath located on a first side of the diaphragm; and a cavity locatedbeneath a second side of the diaphragm; a substrate, wherein thediaphragm of each transducer of the plurality of transducers is locatedon a first side of the substrate; and electrically conductive platinglocated on a second side of the substrate that is opposite the firstside of the substrate, wherein the electrically conductive plating iselectrically charged causing an electrical potential to be applied to atleast one transducer's conductive path, thereby displacing the at leastone transducer's diaphragm.
 2. The array of transducers of claim 1,wherein the diaphragm of the at least one transducer is displaced byelectrical induction, which causes a sound wave to be generated.
 3. Thearray of transducers of claim 1, wherein each transducer's cavity isformed within the substrate.
 4. The array of transducers of claim 3,wherein at least one transducer of the plurality of transducers has itscavity formed within the substrate by etching away at least a portion ofthe substrate.
 5. The array of transducers of claim 1, wherein: thesubstrate is a silicon substrate; and at least one transducer'sdiaphragm is a polymer membrane.
 6. The array of transducers of claim 1,wherein at least one transducer of the array of transducers furthercomprises: at least one acoustic port.
 7. The array of transducers ofclaim 6, wherein the at least one acoustic port extends from the atleast one transducer's cavity through the electrically conductiveplating.
 8. The array of transducers of claim 6, wherein the at leastone acoustic port is formed by etching away at least a portion of thesubstrate.
 9. The array of transducers of claim 1, wherein the diaphragmof at least one transducer of the plurality of transducers is flexible.10. The array of transducers of claim 9, wherein at least one of: thediaphragm is formed of a highly flexible material, such that the atleast one transducer has a high resonant frequency; and the diaphragm isformed of a stiffer material, such that the at least one transducer hasa low resonant frequency.
 11. The array of transducers of claim 1,wherein a resonant frequency of at least one transducer of the pluralityof transducers is a function of a size of that at least one transducer'scavity.
 12. The array of transducers of claim 11, wherein at least onetransducer of the plurality of transducers further comprises at leastone acoustic port, the resonant frequency of that at least onetransducer is further a function of: a size of the at least one acousticport of that at least one transducer; and a number of acoustic portsthat at least one transducer includes.
 13. The array of transducers ofclaim 1, further comprising: at least one control line coupled to eachtransducers conductive path.
 14. The array of claim 13, wherein the atleast one control line comprises: an active conductor and a returnconductor.
 15. A transducer within an array of transducers, comprising:a diaphragm; a conductive path that is at least one: of coupled to, andintegrated into the diaphragm, the conductive path being located on afirst side of the diaphragm; a control line coupled to the conductivepath; and a cavity located beneath the diaphragm, wherein: the diaphragmis located on a first side of a substrate; and electrically conductiveplating is located on a second side of the substrate that is oppositethe first side of the substrate, wherein: the electrically conductiveplating is electrically charged causing current flowing through thetransducer's conductive path to be altered and an electric signal to begenerated via electromagnetic induction; and the electromagneticinduction causes a sound wave to be generated that displaces thediaphragm.